A Power amplifier (PA) is used to receive an analog input signal and deliver an amplified signal with higher amplitude in an electronic device. Of particular interest is a PA that can amplify radio frequency (RF) input signals to drive a radio transmitter or an antenna in a transmitter for application in a battery-powered portable electronic device such as a wireless smart phone. Rapid growth in LTE smart phones has increased the demand for multiband PAs that have low cost and high efficiency. A high efficiency PA has a high ratio of delivered power compared to the total power consumed by the PA.